Update llvm-pass.so.cc

Author: vivian921207

lab6/llvm-pass.so.cc

@@ -1,6 +1,9 @@
 #include "llvm/Passes/PassPlugin.h"
 #include "llvm/Passes/PassBuilder.h"
 #include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Instructions.h"
 
 using namespace llvm;
 
@@ -11,13 +14,35 @@ struct LLVMPass : public PassInfoMixin<LLVMPass> {
 PreservedAnalyses LLVMPass::run(Module &M, ModuleAnalysisManager &MAM) {
   LLVMContext &Ctx = M.getContext();
   IntegerType *Int32Ty = IntegerType::getInt32Ty(Ctx);
-  FunctionCallee debug_func = M.getOrInsertFunction("debug", Int32Ty);
+  PointerType *Int8PtrTy = Type::getInt8PtrTy(Ctx);
+
+  // 宣告 debug(int) 函式
+  FunctionType *DebugFuncTy = FunctionType::get(Type::getVoidTy(Ctx), {Int32Ty}, false);
+  FunctionCallee debug_func = M.getOrInsertFunction("debug", DebugFuncTy);
   ConstantInt *debug_arg = ConstantInt::get(Int32Ty, 48763);
 
-  for (auto &F : M) {
-    errs() << "func: " << F.getName() << "\n";
+  for (Function &F : M) {
+    if (F.getName() != "main") continue;
+
+    // 取得 main 的參數 argc, argv
+    Argument *argc = F.getArg(0);
+    Argument *argv = F.getArg(1);
+
+    // 插入點：main 的開頭
+    IRBuilder<> IRB(&*F.getEntryBlock().getFirstInsertionPt());
+
+    // 1️⃣ 呼叫 debug(48763)
+    IRB.CreateCall(debug_func, debug_arg);
 
+    // 2️⃣ 將 argc 的所有用途替換為常數 48763
+    argc->replaceAllUsesWith(debug_arg);
+
+    // 3️⃣ 將 argv[1] 設為 "hayaku... motohayaku!"
+    Value *argv1_ptr = IRB.CreateGEP(argv->getType()->getPointerElementType(), argv, ConstantInt::get(Int32Ty, 1));
+    Value *str_val = IRB.CreateGlobalStringPtr("hayaku... motohayaku!");
+    IRB.CreateStore(str_val, argv1_ptr);
   }
+
   return PreservedAnalyses::none();
 }
 
@@ -31,4 +56,3 @@ llvmGetPassPluginInfo() {
         });
     }};
 }
-